Method for manufacturing magnetic head

ABSTRACT

According to an aspect of an embodiment, a method for manufacturing a magnetic head includes: providing a substrate; forming a first magnetic layer having a pattern for forming a magnetic pole on the substrate; forming a stopper layer of non-magnetic material on the top and the sides of the first magnetic layer; reducing the thickness of the stopper layer on the top of the first magnetic layer; and forming a second magnetic layer on the stopper layer. The method further includes: polishing the second magnetic layer to expose the stopper layer on the top of the first magnetic layer; and removing the stopper layer on the top of the first magnetic layer, so as to expose the top of the first magnetic layer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-322674 filed on Dec. 14, 2007, the entire content of which is incorporated herein by reference.

BACKGROUND

1. Field

This art relates to magnetic heads for writing information on recording media.

2. Description of the Related Art

In magnetic heads used in magnetic disk devices, the skew angle is varied depending on whether the arm supporting the magnetic head lies at the inner periphery side or at the outer periphery side of the recording medium.

This causes the so-called side track erase problem that information written in the adjacent track is erased, or that the SN ratio of the magnetic recording is reduced. In order to prevent the side track erase problem, the recording magnetic pole has an inverted trapezoidal end face.

As the recording density of recording media is increased, however, the side erase problem becomes noticeably occurring. Accordingly, techniques have been proposed in which side shields are disposed with the magnetic pole in between to prevent the magnetic flux from leaking to the adjacent tracks (Japanese Laid-open Patent Publications No. 2007-52904, No. 2007-35082, and No. 2007-257742).

SUMMARY

According to an aspect of an embodiment, a method for manufacturing a magnetic head includes: providing a substrate; forming a first magnetic layer having a pattern for forming a magnetic pole on the substrate; forming a stopper layer of non-magnetic material on the top and the sides of the first magnetic layer; reducing the thickness of the stopper layer on the top of the first magnetic layer; forming a second magnetic layer on the stopper layer; polishing the second magnetic layer to expose the stopper layer on the top of the first magnetic layer; and removing the stopper layer on the top of the first magnetic layer, so as to expose the top of the first magnetic layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are side views and a plan view of the structure of a main magnetic pole and a trailing shield;

FIGS. 2A to 2D are representations of a process up to the step of forming a first magnetic layer;

FIGS. 3A to 3E are representations of a process up to the step of forming a second magnetic layer;

FIGS. 4A to 4E are representations of a process up to the step of forming a main magnetic pole and side shields;

FIGS. 5A to 5F are representations of a process up to the step of forming a trailing shield, following the formation of the main magnetic pole and the side shields;

FIGS. 6A to 6D are representations of a modification of the first embodiment;

FIGS. 7A to 7F are representations of a manufacturing method according to a second embodiment; and

FIGS. 8A to 8E are representation of a modification of the second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1A to 1C are schematic views of the structure of a recording head including side shields.

FIGS. 1A and 1B show the recording head when viewed from the flying side. This recording head is of perpendicular magnetic recording type. Side shields 12 a and 12 b are disposed at both sides of an inverted trapezoidal main magnetic pole 10, and a trailing shield 14 is disposed over the main magnetic pole 10 and the side shields 12 a and 12 b. The spaces among the main magnetic pole 10, side shields 12 a and 12 b, and the trailing shield 14 are filled with an insulating material, such as Al₂O₃ or SiO₂, or a non-magnetic metal, such as Ta. FIG. 1C is a plan view of the recording head. The main magnetic pole 10 has a narrow end portion having a small width at the ABS (Air-Bearing Surface) side and the width gradually increases in the height direction. The side shields 12 a and 12 b are disposed at both sides of the narrow end portion of the magnetic pole.

In order to form the main magnetic pole 10 of a recording head, for example, a substrate is coated with a resist layer, and the resist layer is patterned so as to form an opening corresponding to the shape of the main magnetic pole. A magnetic material is deposited to raise the level in the opening by plating. Thus, a main magnetic pole is formed. Since the upper surface of the deposition of the magnetic material in the opening is curved, the upper surface is polished to planarize so that the narrow end portion of the magnetic pole can be formed in an inverted trapezoidal shape.

The recording accuracy is significantly affected by the shape of the end face of the main magnetic pole. It is therefore desirable that the main magnetic pole be formed with a proper height (thickness) and core width. An extremely large number of magnetic heads are formed in a substrate. For forming main magnetic poles having a desired shape in the substrate by polishing, the manufacturing process must be carefully performed so that highly precise working can be achieved.

When the side shields are formed in addition to the main magnetic pole, the side shields must be reliably formed without degrading the accuracy in the formation of the main magnetic pole.

Preferred embodiments will now be described in detail with reference to the drawings.

First Embodiment

FIGS. 2A to 5F are representations of a method for manufacturing a magnetic head according to a first embodiment, showing steps for forming a main magnetic pole of a perpendicular magnetic head and side shields disposed with the main magnetic pole in between.

Forming a First Magnetic Layer

FIGS. 2A to 2D are representation of a process up to the step of forming a first magnetic layer 23 intended for the main magnetic pole on the surface of a substrate. The substrate has a read head including a read element.

FIG. 2A shows the state in which a plating seed layer 21 has been formed of, for example, ruthenium on a base layer 20 formed on the surface of the substrate by sputtering.

Then, a resist pattern 22 is formed on the surface of the plating seed layer 21 (FIG. 2B). For forming the resist pattern 22, the surface of the plating seed layer 21 is coated with a resist layer. The resist layer is exposed to light corresponding to a pattern of the main magnetic poles to be formed on the substrate, and is subsequently developed to form an opening (a groove) 22 a in which the plating seed layer 21 is exposed at the bottom. FIG. 2B shows the opening 22 a formed in the resist pattern 22 viewed from the side of the region in which the narrow end of the main magnetic pole will be formed.

Since the narrow end of the main magnetic pole is formed in an inverted trapezoidal shape, the region in the opening 22 a in which the narrow end of the main magnetic pole will be formed is formed in an inverted trapezoidal shape in sectional view. After exposure and development of the resist layer, the open side of the opening 22 a is expanded to have a larger width than the bottom side through a heating step. Thus, the opening 22 a has an inverted trapezoidal section, having an inclined inner wall.

FIGS. 2A to 2D show one of the openings 22 a formed in the resist pattern 22. Many magnetic heads will be formed in the substrate. The resist pattern 22 is formed corresponding to the pattern of the main magnetic poles in the regions where magnetic heads will be formed.

Then, a first magnetic layer 23 is deposited to raise the level in the opening 22 a of the resist pattern 22 by electroplating using the plating seed layer 21 as a plating power supply layer (FIG. 2C). The main magnetic pole has superior soft magnetic characteristics, and is formed of a magnetic material having a high saturation magnetic flux density, such as NiFe or FeCo.

Then, the resist pattern 22 is removed to form the first magnetic layer 23 intended for the main magnetic pole on the surface of the plating seed layer 21 (FIG. 2D).

Forming a Second Magnetic Layer

FIGS. 3A to 3E show a process up to the step of forming a second magnetic layer intended for side shields.

FIG. 3A shows the state in which a stopper layer 24 has been formed. The stopper layer 24 defines side gaps and positions subjected to polishing. A stopper material is deposited on the top and side surfaces the first magnetic layer 23 by sputtering in a slanted direction with respect to the surface of the substrate.

Preferably, the material of the stopper layer 24 is a non-magnetic material that can favorably act as a polishing stopper, such as Ta (tantalum).

The thickness of the stopper material coating the side surfaces of the first magnetic layer 23 near the narrow end defines the interval D of the side gap. The side gap can be therefore controlled by adjusting the sputtering conditions.

FIG. 3B shows the step of reducing the thickness of the stopper layer 24 on the top of the first magnetic layer 23 by ion milling. In the following step, the surface of the substrate is polished to planarize. This polishing step is performed up to the vicinity of the top of the first magnetic layer 23. Accordingly, in order to ensure the polishing step, the stopper layer 24 coating the top of the first magnetic layer 23 is formed to a small thickness that can maintain its function as a stopper in the polishing step, and to a thickness of, for example, 80 nm. The thickness of the stopper layer 24 on the top of the first magnetic layer 23 can be reduced without varying the thickness of the stopper material coating the side surfaces of the first magnetic layer 23, or the interval D of the side gap, by controlling the conditions of ion milling performed on the surface of the substrate.

In the step of reducing the thickness of the stopper layer 24, the surface of the stopper layer 24 directly exposed to the milling ions at portions adjacent to the first magnetic layer 23 is etched simultaneously, the thickness of the stopper layer 24 directly exposed to the milling ions at portions adjacent to the first magnetic layer 23 being reduced. The etching of the surface causes the first magnetic layer 23 to be covered with the side shields widely. In a magnetic disk device having the magnetic head according to the embodiment and a magnetic disk, the side shields effectively prevent the magnetic flux from leaking to the adjacent tracks adjacent to the track where magnetic information is to be written during writing operations. Consequently it is highly unlikely that the side track erase is caused. The larger the interval D of the side gap is, the more effectively the step of reducing the thickness of the stopper layer 24 contributes to preventing the side track erase.

Then, a plating base 25 is formed over the entire surface of the substrate by sputtering (FIG. 3C). The plating base 25 is made of a magnetic metal, such as NiFe or CoNiFe, or a non-magnetic metal, such as ruthenium or copper. Preferably, the plating base 25 is formed of the same material as the material deposited by electroplating.

Then, the surface of the substrate coated with the plating base 25 is further coated with a resist layer. The resist layer is exposed to light and developed to form a resist pattern 26 having an opening (a groove) 26 a at the sides of the narrow end of the first magnetic layer 23 (FIG. 3D). Consequently, the plating base 25 is exposed at the bottom of the opening 26 a. In the opening 26 a, a magnetic layer intended for the side shields is formed at the sides of the main magnetic pole.

The side shields are formed in practice so as to extend to the positions quite distant (about 1 to 25 μm) from the sides of the main magnetic pole. Although FIGS. 3D and 3E show the opening 26 a whose side walls are not much distant from the first magnetic layer 23, the opening 26 a is formed in practice so that the side shields can extend to positions quite distant from the first magnetic layer 23. The same applies to the figures showing the side shields of other embodiments, and the transverse direction of such figures is shown with a smaller scale.

Then, a second magnetic layer 27 is deposited to raise the level in the opening 26 a by electroplating using the plating base 25 as a plating power supply layer (FIG. 3E). The second magnetic layer 27 is formed so as to fill the opening 26 a on a part of the stopper layer 24 at the sides of the first magnetic layer 23.

The second magnetic layer 27 is intended for the side shields. A soft magnetic material having superior shielding properties, such as NiFe, can be used for the second magnetic layer 27. The stopper layer 24 is formed of a material that can be polished at a lower rate (more difficult to polish) than the magnetic material of the second magnetic layer 27. In other words, the second magnetic layer 27 is formed of a magnetic material that can be polished at a higher rate than the stopper layer 24.

Polishing the Second Magnetic Layer

FIGS. 4A to 4E show a process up to the step of polishing the second magnetic layer 27 coating the surface of the substrate to form the side shields.

FIG. 4A shows the state in which the resist pattern 26 has been removed. The resist pattern 26 can be removed by use of an organic solvent or by dry etching.

In the step shown in FIG. 4B, the plating base 25 outside the region coated with the second magnetic layer 27 is removed. The removal of the plating base 25 can be performed by ion milling.

FIG. 4C shows the state in which the second magnetic layer 27 has been coated with an insulating layer 28 to fill the recesses at the sides of the second magnetic layer 27 with the insulating material. The insulating layer 28 is formed of an insulating a material, such as alumina, by sputtering. The second magnetic layer 27 protrudes from the portion under which the first magnetic layer 23 is disposed. Accordingly, the insulating layer 28 has an uneven surface by sputtering the surface of the substrate with an insulating material.

Subsequently, the surface of the substrate is subjected to a first polishing step. In the first polishing step, the insulating layer 28 and the second magnetic layer 27 are polished to planarize the surface of the substrate. The first polishing step can be performed by CMP (Chemical Mechanical Polishing).

FIG. 4D shows the state in which the surface of the substrate has been planarized by the first polishing step. In the first polishing step, the stopper layer 24 coating the top of the first magnetic layer 23 serves as a polishing stopper and stops the progress of polishing when the stopper layer 24 on the top of the first magnetic layer 23 is exposed. Consequently, the surfaces of the second magnetic layer 27 and the insulating layer 28 disposed at the sides of the second magnetic layer 27 become flush with each other with the stopper layer 24 partially exposed at the surface of the substrate.

FIG. 4E shows the state in which the top portion of the stopper layer 24 coating the first magnetic layer 23 has been removed so that the first magnetic layer 23 can be formed into an inverted trapezoidal shape. The stopper layer 24 can be selectively removed by reactive ion etching (RIE).

Forming Side Shields

FIGS. 5A to 5F show a process up to the step of forming a trailing shield after a second polishing step of polishing the surface of the substrate to form the main magnetic pole and side shields.

FIG. 5A shows the state in which the surface of the substrate has been subjected to the second polishing step to planarize the surface. Since the stopper layer 24 has been removed from the top of the first magnetic layer 23 in the preceding step, the second polishing step polishes the first magnetic layer 23 from the top side and thus forms the narrow end of the main magnetic pole 23 a in an inverted trapezoidal shape. The first polishing step roughly planarizes the entire surface of the substrate, and the second polishing step finishes the surface while the amount of polishing is controlled. Thus, highly precise polishing can be performed, and, consequently, each main magnetic pole of the magnetic heads formed on the substrate is finished to a desired shape.

In FIG. 5A, the side shields 27 a formed by polishing the upper surface of the second magnetic layer 27 are disposed with the inverted trapezoidal narrow end of the main magnetic pole 23 a in between, and the stopper layer 24 made of an non-magnetic material is disposed between the sides of the main magnetic pole 23 a and side shields 27 a so that the main magnetic pole 23 a is apart from the side shields 27 a with a predetermined distance.

FIG. 5B shows the state in which a non-magnetic layer 29 has been formed of an insulating material, such as alumina, or a non-magnetic metal by sputtering so that the trailing shield can be formed over the main magnetic pole 23 a with a distance. The non-magnetic layer 29 defines a gap between the main magnetic pole 23 a and the trailing shield, and is formed to a thickness of about 60 nm or less. Since the surface of the substrate is planarized, the non-magnetic layer 29 can be formed to a uniform thickness over the surface of the substrate. This technique can precisely form a gap.

FIG. 5C shows the state in which a resist pattern 30 has been formed on the surface of the substrate so that the non-magnetic layer 29 can be left corresponding to the region where the trailing shield will be formed.

Then, the surface of the substrate is subjected to ion milling through the resist pattern 30 as a mask to remove the portion of the non-magnetic layer 29 exposed at the surface of the substrate. FIG. 6D shows the state after removing the resist pattern 30.

Then, the trailing shield is formed by electroplating, as shown in FIGS. 5E and 5F. In FIG. 5E, a plating seed layer 31 is formed on the surface of the substrate, and then a resist pattern 32 is formed on the surface of the plating seed layer 31. The resist pattern has an opening 32 a in the region where the trailing shield will be formed.

In FIG. 5F, a magnetic material is deposited in the opening 32 a of the resist pattern 32 to form the trailing shield 34 by electroplating using the plating seed layer 31 as a plating power supply layer. Subsequently, after removing the resist pattern 32, the portion of the plating seed layer 31 exposed at the surface of the substrate is removed.

A return yoke is formed on the trailing shield 34. After the step shown in FIG. 5F, the surface of the substrate is coated with an insulating material, such as alumina, so as to dispose the insulating material between the layers, followed by polishing to planarize the surface of the substrate. Then, the return yoke is formed so as to join to the trailing shield 34.

Thus, a read head is completed which includes the side shields 27 a disposed with the inverted trapezoidal narrow end of the magnetic pole 23 a in between, and the trailing shield 34 over the main magnetic pole 23 a with a predetermined distance.

In the magnetic head produced in practice, the side shields 27 a extend to positions quite distant from the main magnetic pole 23 a, unlike the structure shown in FIG. 5F, as mentioned above. Also, the trailing shield 34 has a larger thickness than the state shown in FIG. 5F.

Modification

FIGS. 6A to 6D show a modification of the method for manufacturing a magnetic head according to the first embodiment. FIG. 6A shows the step of forming the first magnetic layer 23 shown in FIG. 2C. In the first embodiment, the first magnetic layer 23 is formed corresponding to the shape of the section of the narrow end of the main magnetic pole. On the other hand, in this modification, the first magnetic layer 23 is formed into a shape having a larger section than that of the narrow end of the main magnetic pole by a polishing allowance for ion milling.

FIG. 6B shows the following step in which the substrate is subjected to ion milling to etch the first magnetic layer 23 in such a manner that the narrow end of the main magnetic pole has an inverted trapezoidal section. In the ion milling step, the first magnetic layer 23 is etched into a desired shape of the main magnetic pole, and simultaneously the surface of the substrate is polished so as to remove part of the plating seed layer 21 or the entire plating seed layer and part of the base layer 20 at the sides of the first magnetic layer 23.

FIG. 6C shows the state in which not only the plating seed layer 21, but also part of the base layer 20 has been removed.

In this method, the first magnetic layer 23 is formed into a desired shape of the main magnetic pole by ion milling. In addition, this method allows the underlying layer of the first magnetic layer 23 to be etched to the level lower than the bottom of the first magnetic layer 23.

By etching the plating seed layer 21 or further etching the base layer 20 at the sides of the first magnetic layer 23 to the level lower than the bottom of the first magnetic layer 23, the side shields 27 a, which are formed in a subsequent step, can shield the entire main magnetic pole 23 a in the height direction (thickness direction).

FIG. 6D shows the state in which the main magnetic pole 23 a and the side shields 27 a have been formed through completely the same steps shown in FIGS. 4A to 4E and 5A to 5F after the step shown in FIG. 6C.

Since the plating seed layer 21 and the base layer 20 are etched to a level lower than the bottom of the first magnetic layer 23, the bottoms of the side shields 27 a lie below the bottom of the main magnetic pole 23 a and the sides of the main magnetic pole 23 a are covered with the side shields 27 a. The positional relationship between the side shields 27 a and the main magnetic pole 23 a is clearly different from that shown in FIG. 5F.

By shielding the sides of the main magnetic pole 23 a including the portion around the bottom by the side shields 27 a, as described above, the recording magnetic pole can be shielded on the sides effectively.

Second Embodiment

In the first embodiment, a side gap layer is formed by sputtering a single stopper material after forming the first magnetic layer 23, as shown in FIGS. 3A and 3B, so that the side gap layer can serve as a polishing stopper. In the magnetic head manufacturing method shown in FIGS. 7A to 7F, the stopper layer and the side gap layer are formed of respective materials.

FIG. 7A shows the state in which a stopper layer 24 a has been formed to a thickness sufficient to act as a polishing stopper on the top of the first magnetic layer 23. The stopper layer 24 a is formed of a stopper material, such as Ta, by sputtering. The sputtering step deposits the stopper material on the top and side surfaces of the first magnetic layer 23. The thickness of the stopper layer 24 a on the sides of the first magnetic layer 23 is smaller than that on the top of the first magnetic layer 23. The stopper layer 24 a on the side surfaces of the first magnetic layer 23 defines part of the side gap layer.

FIGS. 7B and 7C show the step of forming a first insulating layer 24 b on the sides of the first magnetic layer 23. The first insulating layer 24 b defines a side gap layer together with the stopper layer 24 a formed on the sides of the first magnetic layer 23 in the preceding step. The first insulating layer 24 b is formed by sputtering an insulating material, such as alumina, onto the surface of the substrate.

FIG. 7B shows the state in which the first insulating layer 24 b has coated the surface of the stopper layer 24 a including the portions on the sides of the first magnetic layer 23. Since the thicknesses of the stopper layer 24 a on the side surfaces of the first magnetic layer 23 and the first insulating layer 24 b coating the side surfaces of the stopper layer 24 a define the side gap, the thickness of the first insulating layer 24 b is controlled so that the entire side gap layer form a predetermined side gap.

Then, the surface of the substrate is subjected to ion milling to remove the first insulating layer 24 b coating the top of the first magnetic layer 23 until the stopper layer 24 a is exposed (FIG. 7C). In this instance, the first insulating layer 24 b is not necessarily removed so as to expose the entire surface of the stopper layer 24 a, and part of the first insulating layer 24 b may be left. The material of the first insulating layer 24 b is selected from the materials that can be polished at a higher rate (easier to polish) than the stopper material of the stopper layer 24 a. Preferably, the surface of the stopper layer 24 a is exposed in the step shown in FIG. 7C, so that the subsequent polishing can be performed precisely.

Then, a plating base 25 is formed over the entire surface of the substrate by sputtering. FIG. 7D shows the state in which the plating base layer 25 has been formed over the surface of the substrate.

After forming the plating base 25, the same steps as in the first embodiment are performed.

FIG. 7E shows the state in which a second magnetic layer 27 has been formed in an opening 26 a of a resist pattern 26 formed on the surface of the substrate, by electroplating using the plating base 25 as the plating power supply layer. Then, the resist pattern 26 is removed, and the surface of the substrate is coated with a second insulating layer made of an insulating material, such as alumina, to planarize the surface of the substrate. Thus, the main magnetic pole 23 a and the side shields 27 a are completed.

In the present embodiment as well, the surface of the substrate is planarized by the first polishing step to a height at which the surface of the stopper layer 24 a is exposed. The top of the stopper layer 24 a is selectively removed by RIE, and thus, the main magnetic pole 23 a and the side shields 27 a are formed. FIG. 7F shows the state in which a trailing shield 34 has been formed after the formation of the main magnetic pole 23 a and the side shields 27 a. In the present embodiment, a gap is formed between the side shields 27 a and the trailing shield 34, using a non-magnetic layer 29.

Modification

FIGS. 8A to 8E show a modification of the method for manufacturing a magnetic head according to the second embodiment. In the step shown in FIG. 8A, the first magnetic layer 23 is formed, and then, ion milling is performed using the first magnetic layer 23 as a mask so that the narrow end of the first magnetic layer 23 is etched into a desired inverted trapezoidal shape and so that the plating seed layer 21 at the sides of the first magnetic layer 23 or the plating seed layer 21 and part of the base layer 20 below the first magnetic layer 23 are etched to a level lower than the bottom of the first magnetic layer 23, in the same manner as in the steps shown in FIGS. 6A to 6D.

FIG. 8B shows the state in which the top of the first magnetic layer 23 has been coated with a stopper layer 24 a. The side surfaces of the first magnetic layer 23 are also coated with the stopper layer 24 a with a small thickness. FIG. 8C shows the state in which ion milling is performed on the surface of substrate after forming a first insulating layer 24 b defining the side gap together with the stopper layer 24 a coating the side surfaces of the first magnetic layer 23.

FIG. 8D shows the state in which the first insulating layer 24 b coating the top of the first magnetic layer 23 has been removed to expose the stopper layer 24 a by ion milling. The steps shown in FIGS. 8B to 8D are performed in the same manner as the steps shown in FIGS. 7A to 7C.

The following steps are performed in completely the same manner as the steps shown in FIGS. 7D to 7F, and thus a read head having side shields 27 a at the sides of the main magnetic pole 23 a is completed (FIG. 8E).

In the read head of the present modification, the bottoms of the side shields 27 a lie below the bottom of the main magnetic pole 23 a and the side surfaces of the main magnetic pole 23 a are covered with the side shields 27 a entirely in the height direction. Consequently, the magnetic pole can be shielded effectively by the side shields 27 a.

In the magnetic head manufacturing method according to the present embodiment, a recording magnetic pole having side shields can be precisely formed in a desired shape with the distances between the side shields and the magnetic pole controlled. In particular, even in a process manufacturing an extremely large number of magnetic heads on a wafer, the end face of the main magnetic pole of each magnetic head can be precisely formed by, for example, polishing a structure in which the top of the first magnetic layer is coated with a stopper layer.

Since in the method according to the embodiments, the side gaps and the gap between the main magnetic pole and the trailing shield are formed in different steps, each gap can be formed precisely.

Since the method according to the embodiments has the step of reducing the thickness of the stopper layer, the first magnetic layer is covered with the side shields widely. In a magnetic disk device having the magnetic head according to the embodiment and a magnetic disk, the side shields effectively prevent the magnetic flux from leaking to adjacent tracks adjacent to the track where magnetic information is to be written during writing operations. Consequently it is highly unlikely that the side track erase is caused.

While the above described embodiments illustrate methods for manufacturing a perpendicular magnetic head including a main magnetic pole, an another embodiment may be applied to methods for manufacturing longitudinal magnetic heads. 

1. A method for manufacturing a magnetic head comprising: providing a substrate; forming a first magnetic layer having a pattern for forming a magnetic pole on the substrate; forming a stopper layer of non-magnetic material on the top and the sides of the first magnetic layer; reducing the thickness of the stopper layer on the top of the first magnetic layer; forming a second magnetic layer on the stopper layer; polishing the second magnetic layer to expose the stopper layer on the top of the first magnetic layer; and removing the stopper layer on the top of the first magnetic layer, so as to expose the top of the first magnetic layer.
 2. The method according to claim 1, wherein the stopper is formed of tantalum.
 3. The method according to claim 1, wherein forming the first magnetic layer includes: forming a plating seed layer on the substrate; forming a resist pattern on the plating seed layer, the resist pattern having an opening in which the plating seed layer is exposed at the bottom; and electroplating by using the plating seed layer as a plating power supply layer so as to form the first magnetic layer on a part of the plating seed layer in the opening.
 4. The method according to claim 1, further comprising: etching the upper side of the substrate by using the first magnetic layer as a mask.
 5. The method according to claim 3, further comprising: etching the plating seed layer by using the first magnetic layer as a mask after forming the first magnetic layer.
 6. The method according to claim 5, further comprising: etching the upper side of the substrate by using the first magnetic layer as a mask.
 7. The method according to claim 1, further comprising: polishing the surface of the substrate to finish the surface after removing the stopper layer.
 8. The method according to claim 1, further comprising: forming on the stopper layer a resist pattern having an opening exposing a part of the stopper layer where the first magnetic layer is disposed, wherein the second magnetic layer is formed on the part of the stopper layer in the opening; and removing the resist pattern after forming the second magnetic layer.
 9. The method according to claim 1, further comprising: forming an insulating layer on the second magnetic layer, wherein by polishing the second magnetic layer, the insulating layer is polished simultaneously with the second magnetic layer to form a common plane.
 10. A method for manufacturing a magnetic head comprising: providing a substrate; forming a first magnetic layer having a pattern for forming a magnetic pole on the substrate on the substrate; forming a stopper layer of non-magnetic material on the top of the first magnetic layer; forming a first insulating layer on the top of the stopper layer and the sides of the first magnetic layer, the first insulating layer capable of being polished at a higher rate than the stopper layer; reducing the thickness of the first insulating layer on the top of the stopper layer formed on the top of the first magnetic layer; forming a second magnetic layer on the stopper layer; polishing the second magnetic layer to expose the stopper layer on the top of the first magnetic layer; and removing the stopper layer on the top of the first magnetic layer, so as to expose the top of the first magnetic layer.
 11. The method according to claim 10, wherein the first insulating layer is formed of alumina.
 12. The method according to claim 10, wherein the stopper is formed of tantalum.
 13. The method according to claim 10, wherein forming the first magnetic layer includes: forming a plating seed layer on the substrate; forming a resist pattern on the plating seed layer, the resist pattern having an opening in which a part of the plating seed layer is exposed; and electroplating by using the plating seed layer as a plating power supply layer so as to form the first magnetic layer on a part of the plating seed layer in the opening.
 14. The method according to claim 10, wherein the stopper layer of non-magnetic material is further formed on the side of the first magnetic layer.
 15. The method according to claim 10, further comprising: etching the upper side of the substrate by using the first magnetic layer as a mask.
 16. The method according to claim 13, further comprising: etching the plating seed layer by using the first magnetic layer as a mask after forming the first magnetic layer.
 17. The method according to claim 16, further comprising: etching the upper side of the substrate by using the first magnetic layer as a mask.
 18. The method according to claim 10, further comprising: polishing the surface of the substrate to finish the surface after removing the stopper layer.
 19. The method according to claim 10, further comprising: forming on the stopper layer a resist pattern having an opening exposing a part of the stopper layer where the first magnetic layer is disposed, wherein the second magnetic layer is formed on the part of the stopper layer in the opening; and removing the resist pattern after forming the second magnetic layer.
 20. The method according to claim 10, further comprising: forming a second insulating layer wherein by polishing the second magnetic layer, the second insulating layer is polished simultaneously with the second magnetic layer to form a common plane. 